Mobile communication systems have been required to ensure service qualities in accordance with the contents of communication requests randomly made by mobile stations (users). Thus, when installing a base station, a mobile telecommunications carrier generally estimates the size of a service area and traffic generated in the service area, and uses means such as simulation to design the installation location and configuration of the base station as well as radio parameters such as a transmission level of a downlink common control channel transmitted from the base station.
In addition, in designing such a base station, an in-out reception level is determined which is a reception level indicating whether or not a mobile station is to camp on a cell formed by the base station. For example, in the case of the W-CDMA system, a mobile station camps on the cell when a measured RSCP exceeds Qrxlevmin based on the Qrxlevmin broadcasted from the cell whose measured RSCP is the highest. On the other hand, when the regularly-measured Received Signal Code Power (RSCP) becomes equal to or lower than the Qrxlevmin after completion of the procedure to camp on the cell, the mobile station tries to camp on another cell.
Furthermore, recently, small-sized base stations (Home NodeB) installed by users of mobile stations at home or the like have been increased in addition to base stations for public communications installed by the above-described mobile telecommunications carrier. In the case of a small-sized base station, the users are limited and the size of the cell is small compared with the base station for public communications. Thus, an increase in throughput can be expected (see, NON-PATENT DOCUMENT 1)